Use the Indicated Change of Variables to Evaluate the Following $$x = \frac { 1 } { 2 } ( u + v ) , y = - \frac { 1 } { 2 } ( u - v )$$

Multiple Choice

Use the indicated change of variables to evaluate the following double integral. $$x = \frac { 1 } { 2 } ( u + v ) , y = - \frac { 1 } { 2 } ( u - v )$$
$\iint_{R} 60 x y d A$

A) 128
B) 120
C) $- 120$
D) 118
E) 60